46  U1241A/U1242A User’s and Service Guide
5 Performance Tests and Calibration
Calibration Security
The calibration security code prevents accidental or unauthorized adjust-
ments to the meter. The meter is secured when the meter is shipped from 
factory. Before performing any adjustment to the meter, you are required 
to unsecure the meter by entering the correct security code (see Unsecur-
ing the Meter for Calibration). The security code may contain up to 4 
numeric characters.
Unsecuring the Meter for Calibration
Before performing adjustment to the meter, you are required to unsecure 
the meter by entering the correct security code. The security code is set to 
1234 when the meter is shipped from the factory. The security code is 
stored in non- volatile memory, and does not change when power is off. 
Unsecuring the Meter from the Front Panel
1 Turn the rotary switch to   .
2 Press   and   simultaneously to enter the Calibration 
Security Code entry mode. The primary display shows 5555 and the 
secondary display shows SEU.
3 Press   or   to step each character in the code. Press   
or  to change the value of the selected character.
4 Press   (Save) when done.
5 If the correct security code is entered, the secondary display will show 
“PAS”. If an invalid code is entered, the meter will shows error code 
You can unsecure and change the security code from the meter front panel. If you forget 
your security code, see Unsecuring the Meter Without the Security Code.